Process of manufacturing artificial lustrous threads, &amp;c.



EU it FRIEDRICH EMIL DIETLEBI, QF KELSTERBACH ON-THE-MAIN, GERMANY,ASSIGNOR TO VEREINIGTE KUNSTSEIDEFABRIKEN A. G., OF KELSTEBBAH0N-THE-MAIN, GER- MANY, A conronarron or GERMANY.

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LEZLQOFS.

No Drawing.

Manufacturing Artificial Lustrous Threads,

&c., of which the following is a specification.

My invention is concerned with methods of producing highly lustrousthreads, filas ments and like articles from viscose, and relatesparticularly to the composition of the precipitation bath employed inone of the steps of the method.

The use of an acidulated bath for the production of water solublexanthogenate threads from viscose and the subsequent con version of thexanthogenate into water insoluble cellulose hydrate has been heretoforesuggested. No indication, however, was given as to the nature of thebath to'be employed, nor was there any hint of the quantity of acid tobe introduced in order to produce commercially satisfactory, lustrous,threads. Extensive experiments have shown that it is not always possibleto produce commercially satisfactory, lustrous threads, by treating suchthreads in a bath consisting of a saturated salt solution to which acidhas been added. If, for example, sulfuric acid is employed and sodiumbisulfate is dissolved therein, so that the content of free sulfuricacid amounts to about20%, ex eriments have demonstrated that a bathothis kind will effect animmediate conversion of the viscose into waterinsoluble cellulose hydrate, but the thread treated will notbe'lustrous. If the addition of the sulfuric acid to the saturatedsodium sulfate solution is less. in quantity, for example 6 to 7%, thereis no product. By acidulating the saturated .salt

solution with but a small quantity of sulfuric acid, for example 0.5%,the precipita- Specification of Letters Patent. Application filed June18, i912. Serial No. 704,269.

specific gravity.

Patented Dec. 22, 191%.

tion (salt removal) proceeds too slowly. The several disadvantages abovereferred to are obviated, as I have ascertained, if the quantity ofsulfuric acid added to the salt so lution is between 1 and 5%. I

A bath according to my invention'may be prepared as follows :-Dissolve10 parts of neutral sodium sulfate in 100 parts of water, and add tothis salt solution 1 to 5 parts of sulfuric acid, 1.84'specific avity.The bath thus produced not only e eets a rapid precipitation of ,thexanthogenate, but, moreover, there-are no sulfurous exudations on thesurfaceof the product. To convert the product into water insolublecellulose hydrate it is subjected to the usual treatment of heating,treatment in a bath of common salt, etc. The product finally obtained ishighly lustrous, strong and elastic.

1. The herein described process of manufacturing artificial, lustrousthreads, bands and filaments, which consists in forming viscose solutioninto thread like bodies, and thereafter. subjecting the same to theaction of a precipitation bath consisting of a salt solution containingnot exceeding five per centum of acid. I

2. The herein described process of manufacturing artificial, lustrousthreads, bands and filaments, which consists in forming viscose solutioninto thread like bodies, and thereafter subjecting the same to' theaction of a recipitation bath consisting of a satu rated salt solutioncontaining not exceeding fivevper centum of sulfuric acid.

3. The herein described process of manufacturing artificial, lustrousthreads, bands and filaments, which consists in forming viscose solutioninto thread like bodies, and thereafter subjecting the same to theaction .of a precipitation bath consistingof a solution often parts ofneutral sodium sulfate in one hundred parts of water, and not exceedingfive parts of sulfuric acid of 1.84

4. The herein described process of manufacturing artificial, lustrousthreads, bands and-filaments, which consists in forming viscose solutioninto thread like bodies, thereafter subjecting the same to the action ofa In testimony whereof I have aflixeol my precipitation bath consistingof a solution of signature in presence of two Witnesses. ten parts-0fneutral sodium sulfate in one FRIEDRICH EMIL DIETLER hundred parts ofWater and not exceeding 5 five arts of sulfuric acid of 1.84 specificWitnesses:

gravlty, and finally converting the product JEAN GRUND, into waterinsoluble cellulose hydrate. CARL GRUND.

